US4669401A - Lockstitch sewing machine with a rotary hook - Google Patents

Lockstitch sewing machine with a rotary hook Download PDF

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Publication number
US4669401A
US4669401A US06/811,648 US81164885A US4669401A US 4669401 A US4669401 A US 4669401A US 81164885 A US81164885 A US 81164885A US 4669401 A US4669401 A US 4669401A
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US
United States
Prior art keywords
bobbin
finger
housing
bobbin housing
hook
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/811,648
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English (en)
Inventor
Albert Dusch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PFAFF INUDSTRIEMASCHINEN GmbH
Pfaff Industriemaschinen GmbH
Original Assignee
Pfaff Industriemaschinen GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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Assigned to PFAFF INUDSTRIEMASCHINEN GMBH reassignment PFAFF INUDSTRIEMASCHINEN GMBH ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DUSCH, ALBERT
Application granted granted Critical
Publication of US4669401A publication Critical patent/US4669401A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B57/00—Loop takers, e.g. loopers
    • D05B57/08—Loop takers, e.g. loopers for lock-stitch sewing machines
    • D05B57/10—Shuttles
    • D05B57/14—Shuttles with rotary hooks
    • D05B57/143—Vertical axis type

Definitions

  • the hook is operated with a capsule release device.
  • this device imparts to the bobbin housing a rotational impulse opposite to the direction of hook rotation, whereby a thread passage gap is formed briefly between the holding finger and the rear cam.
  • the bobbin housing is again taken along in the direction of hook rotation, whereby now a thread passage gap is formed between the holding finger and the front cam.
  • German Pat. No. OS 33 03 033 it is proposed to connect the holding finger which serves to prevent rotation of the bobbin housing firmly with the base plate outside the area of the stitch hole and to let its free end engage radially to the hook axis into a U-shaped cutout in the bobbin capsule.
  • the holding finger is to be arranged diametrically to the stitch hole.
  • a supporting finger which serves as protection against reverse rotation, and whose free end protruded into a cutout in the bobbin carrier and cooperates with a first abutment surface formed by the latter.
  • a capsule release device is provided, the finger of which cooperates with a second abutment surface formed by an upwardly extending shoulder.
  • This invention provides a rotary hook where the holding means which prevent co-rotation and reverse rotation of the bobbin housing are arranged so that they hinder the looping of the needle thread loop, and in particular the pull-back movement of the needle thread loop occurring after its maximum expansion, as little as possible.
  • the needle thread loop slides almost without a jerk over the lateral faces of the shoulder, which are substantially tangential to the outer surface of the bobbin housing, so that the shoulder has practically no negative influence on the thread movement and the subsequent stitch insertion in the work. Since during the pull-back of the needle thread loop the bobbin capsule applies by its holding finger against the cam and hence there is a thread passage gap between the support finger and the shoulder, and since moroever the needle thread loop still slides along closely at the front, ascending lateral face of the shoulder during the first part of its pull-back movement, the needle thread never comes in contact with the support finger, so that it can have no influence at all on the thread movement.
  • the rotary hook according to the invention thus distinguishes itself by a motion of the needle thread loop which has especially little jerkiness and friction, and this in particular during the phase crucial for satisfactory stitch formation, namely during the pullback of the needle thread loop. In this way, not only is an always satisfactory stitch insertion of the threads into the work achieved, but also the needle thread tension and hence the danger of thread rupture can be reduced.
  • a further object of the invention is to provide a sewing machine having an improved rotary hook construction which is simple in design, rugged in construction and economical to manufacture.
  • FIG. 1 is a side elevational view of a sewing machine constructed in accordance with the invention
  • FIG. 2 is a side elevational view of the sewing machine rotary hook, the capsule release device being omitted in the interest of greater clarity;
  • FIG. 3 is an end elevational view onto the rotary hook and the capsule release device
  • FIG. 4 is a top perspective view of the rotary hook
  • FIG. 5 is a side sectional view of the rotary hook taken on an opposite side from that shown in the elevational view of FIG. 2.
  • the invention embodied therein comprises a lockstitch sewing machine which has a stitch plate 24 with a rotary hook therebelow of improved construction.
  • the rotary hook includes a revolving hook body 18 on which is supported a rotatable bobbin housing having a housing 20 whose periphery is designated 27 and which has a shoulder 31 that extends to the side and is formed by two appendages 29 and 30.
  • a cam 25 is supported on stitch plate adjacent the bobbin housing and a holding finger 23 is adjacent the cam 25.
  • the holding finger 23 and the cam 25 secure the housing against co-rotation with the hook body 18.
  • a fixed supporting finger 35 cooperates with the bobbin housing 20 and it has a first abutment surface adjacent the bobbin housing.
  • Bobbin housing 20 comprises a bobbin capsule 22 and a capsule carrier 21 which carries the capsule.
  • Bobbin housing 20 is rotatably supported on hook body 18.
  • the construction includes a bobbin capsule release generally designated 44 which includes a capsule release finger 43 with a second abutment surface adjacent the bobbin housing 20.
  • the stitch plate has a stitch hole 26 for the penetration of the threaded needle 6.
  • the cam 25 is adjacent to but behind in the direction of the hook rotation A, the stitch hole 26.
  • the bobbin housing 20 has faces to be described later, against which the abutment surfaces defined by the supporting finger and the capsule release finger, are engageable.
  • the shoulder 31 is arranged at substantially 90° before the stitch hole.
  • the sewing machine includes a base plate 1, a standard 2, and an arm 3 with a head 4.
  • an arm shaft 5 which is in drive connection with a needle bar 7 movable up and down in head 4 and carrying a threaded needle 6.
  • a thread take-up lever 8 which, in a known manner, cooperates with the needle 6 and executes an up and down movement, and which is also driven by the arm shaft 5.
  • a thread tensioning device 9 is arranged.
  • a belt pulley 10 Secured on the arm shaft 5 is a belt pulley 10 which via a belt 11 and a belt pulley 12 transmits the drive movement of the arm shaft 5 to the hook drive shaft 13 mounted in the base plate 1, in the speed ratio 1:1.
  • a bevel gear 14 Secured on the hook drive shaft is a bevel gear 14 which meshes with a counter-gear 16 disposed on the vertical hook shaft 15 and thus drives in the ratio 1:2 the lockstitch rotary hook 17 disposed at the upper end of the hook shaft 15 and revolving in a horizontal plane.
  • the lockstitch rotary hook 17 has the hook body 18 and a hook tip 19 formed thereon.
  • the bobbin housing 20 is supported, which comprises the bobbin capsule 22.
  • the laterally projecting holding finger 23 is formed on a bobbin capsule carrier 21.
  • the cam 25 secured on the underside of the stitch plate 24 recessed in the base plate 1, which cam is arranged a small distance behind the stitch hole 26 in the direction of hook rotation A.
  • the two projections 29 and 30 project laterally from the outer surface or periphery 27 of the bobbin housing 20 and are separated from each other by only a narrow gap and together they form the triangular shoulder 31.
  • the outer side of projection 29 forms what, in the direction of hook rotation A, is the front side face 32 of shoulder 31.
  • the outer side of projection 30 forms what, in the direction of hook rotations A, is the rear side face 33 of shoulder 31. Both faces 32 and 33 are substantially tangential to the outer surface 27 of the bobbin housing 20.
  • the flat supporting finger 35 is attached on the base plate 1, the rounded free end of which is opposite the front side face 32 of shoulder 31.
  • the bobbin housing 20 With the sewing machine running, the bobbin housing 20 is supported by the holding finger 23 on cam 25, and this hinders the rotation of a bobbin housing 20 along with the hook ody 18.
  • a relatively large gap 36 exists between the front end of the supporting finger 35 and the front side face 32 of shoulder 31. Finger 35 functions to prevent reverse rotation of the bobbin housing by engaging against front side face 32.
  • an eccentric 37 is secured, which has a spherical circumferential surface.
  • the eccentric 37 is spanned by one end of an eccentric rod 38, the other end of which carries a spherically shaped head 39.
  • the head 39 is spanned by a socket 40 which is arranged on a crank 42 secured on a vertically mounted shaft 41. Clamped on shaft 41 is the horizontally extending finger 43, whose free end is opposite the rear side face 33 of shoulder 31, the long side of finger 43 toward shoulder 31 being substantially parallel to the rear side face 33. Parts 37 to 43 form the capsule release device 44.
  • the hook tip 19 After the start of stitch formation the hook tip 19 has seized the needle thread loop N formed by the needle 6, the finger 43 driven by eccentric 37 moves against the rear side face 33 and imparts to the bobbin housing 20 a rotational impulse directed counter to the direction of hook rotation A, owing to which the holding finger 23 moves away from cam 25. In this manner, the needle thread loop N can be moved by the hook body 18 through the gap between the holding finger 23 and cam 25.
  • the resulting deflection of the needle thread loop N and the inhibition of the thread movement caused thereby occurs at a time when loop N is being expanded still further and thus the thread slack previously created by the thread take-up liner is used up. At this time of looping a brief impediment of the thread movement has no adverse influence on the stitch formation, because irregular thread movements are compensated during the further expansion of the needle thread loop.
  • the thread take-up lever 8 begins to pull the needle thread loop N back.
  • the eccentric 37 has moved the finger 43 away from shoulder 31, and the bobbin housing 20 has co-rotated with the hook body 18 in the direction of hook rotation A, owing to which the holding finger 23 abuts on cam 25 again.
  • the needle thread loop N drops off the hook tip 19, moves unhindered through the gap 36 between the supporting finger 35 and the front side face 32, and then slides over the tip to shoulder 31 almost without a jerk.
  • the needle thread loop N is moved by the thread feeder 8 through the gap 45 between the finger 43 and the rear side face 33 and is finally pulled back completely through the stitch hole together with a section of the hook thread G.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US06/811,648 1984-12-20 1985-12-20 Lockstitch sewing machine with a rotary hook Expired - Fee Related US4669401A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3446548 1984-12-20
DE3446548A DE3446548C1 (de) 1984-12-20 1984-12-20 Doppelsteppstichnähmaschine mit einem Greifer

Publications (1)

Publication Number Publication Date
US4669401A true US4669401A (en) 1987-06-02

Family

ID=6253348

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/811,648 Expired - Fee Related US4669401A (en) 1984-12-20 1985-12-20 Lockstitch sewing machine with a rotary hook

Country Status (5)

Country Link
US (1) US4669401A (de)
JP (1) JPS61146292A (de)
BR (1) BR8506064A (de)
DE (2) DE3446548C1 (de)
IT (2) IT1184028B (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004059064A1 (de) * 2002-12-28 2004-07-15 Dürkopp Adler Aktiengesellschaft Nähmaschine
US20050104357A1 (en) * 2003-11-18 2005-05-19 Pamela Olson Clothing protection sleeve
CN101413188B (zh) * 2007-10-20 2012-10-10 杜尔克普-阿德勒股份公司 缝纫机及其钩件***
CN101413189B (zh) * 2007-10-20 2012-12-12 杜尔克普-阿德勒股份公司 缝纫机及其钩件***

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002186795A (ja) * 2000-12-20 2002-07-02 Juki Corp 水平釜のオープナー装置
DE102007050244A1 (de) * 2007-10-20 2009-04-23 Dürkopp Adler AG Nähmaschine und Greifer-System für Nähmaschine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1351869A (en) * 1918-04-24 1920-09-07 Singer Mfg Co Sewing-machine loop-taker
US1809391A (en) * 1929-05-10 1931-06-09 Singer Mfg Co Sewing machine loop-taker mechanism
DE566188C (de) * 1930-10-28 1932-12-17 Pfaff Ag G M Doppelsteppstichnaehmaschine mit in waagerechter Ebene frei laufendem Greifer
US2866425A (en) * 1955-06-14 1958-12-30 Union Special Machine Co Lockstitch sewing machines
DE3303033A1 (de) * 1983-01-29 1984-08-02 Kochs Adler Ag, 4800 Bielefeld Doppelsteppstich-greifer fuer eine naehmaschine

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE521407C (de) * 1929-09-24 1931-03-21 Singer Mfg Co Doppelsteppstichnaehmaschine mit OEffnungsfinger und Anhalteteilen fuer den Spulentraeger in einem Horizontalgreifer
JPS57148985A (en) * 1981-03-06 1982-09-14 Mitsubishi Electric Corp Opener device for sewing machine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1351869A (en) * 1918-04-24 1920-09-07 Singer Mfg Co Sewing-machine loop-taker
US1809391A (en) * 1929-05-10 1931-06-09 Singer Mfg Co Sewing machine loop-taker mechanism
DE566188C (de) * 1930-10-28 1932-12-17 Pfaff Ag G M Doppelsteppstichnaehmaschine mit in waagerechter Ebene frei laufendem Greifer
US2866425A (en) * 1955-06-14 1958-12-30 Union Special Machine Co Lockstitch sewing machines
DE3303033A1 (de) * 1983-01-29 1984-08-02 Kochs Adler Ag, 4800 Bielefeld Doppelsteppstich-greifer fuer eine naehmaschine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004059064A1 (de) * 2002-12-28 2004-07-15 Dürkopp Adler Aktiengesellschaft Nähmaschine
US20050039657A1 (en) * 2002-12-28 2005-02-24 Christoph Heckner Sewing machine
US6923130B2 (en) 2002-12-28 2005-08-02 Dürkopp Adler Aktiengesellschaft Sewing machine
US20050104357A1 (en) * 2003-11-18 2005-05-19 Pamela Olson Clothing protection sleeve
CN101413188B (zh) * 2007-10-20 2012-10-10 杜尔克普-阿德勒股份公司 缝纫机及其钩件***
CN101413189B (zh) * 2007-10-20 2012-12-12 杜尔克普-阿德勒股份公司 缝纫机及其钩件***

Also Published As

Publication number Publication date
IT8568076A0 (it) 1985-12-19
IT8554253V0 (it) 1985-12-19
DE3446548C1 (de) 1986-01-09
JPH0134636B2 (de) 1989-07-20
BR8506064A (pt) 1986-08-19
IT1184028B (it) 1987-10-22
JPS61146292A (ja) 1986-07-03
DE8437345U1 (de) 1986-09-18

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AS Assignment

Owner name: PFAFF INUDSTRIEMASCHINEN GMBH, KONIGSTRASSE 154, D

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DUSCH, ALBERT;REEL/FRAME:004512/0187

Effective date: 19851105

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Effective date: 19950607

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362